In recent years, in CCD (charge coupled device) type solid-state imaging devices, because of microminiaturization, problems have arisen such as the rise of the depletion voltage of the photoelectric conversion elements and the increase in the smear charge flowing into the CCD from the surfaces of the photoelectric conversion elements during the exposure period and the charge transfer period. Accordingly, to solve these problems, it has previously been proposed to suppress the rise of the depletion voltage of the photoelectric conversion elements by applying a positive voltage to the shielding layer during the period of charge reading from the photoelectric conversion elements to the CCD and prevent the smear charge from moving into the CCD by applying a negative voltage to a shielding layer that shields the part, other than the light receiving surface, of the photoelectric conversion elements during the period other than that (see, for example, JP-A-2005-109021).
It has also been proposed to form a transparent electrode layer on the apertures of the photoelectric conversion elements, apply a positive voltage to the transparent electrode layer during the charge reading period and apply a negative voltage thereto during the period other than the charge reading period (see, for example, JP-A-2006-121112 (corresponding to US2002/0195628A1) and JP-A-2003-37262 (corresponding to US2002/0195628A1)).